It is known that various naturally occurring polysaccharides such as pea xyloglucan, tamarind seed xyloglucan, etc. bind to cellulose by a polysaccharide:polysaccharide interaction; indeed this binding ability is important in the functioning of plant cell walls.
U.S. Pat. No. 3,297,604 concerns polymer compositions containing galactose oxidized to form a carbonyl group at the C6 position. The active carbonyl group can react in known manner, e.g. to form cyano hydrins, bisulfite addition compounds, oximes, hydrazones, etc. The compositions can also act to cross-link polymers, including cellulose. The polymer, may be, e.g., guar, locust bean gum, etc. There is no disclosure of a polysaccharide conjugate with attached entity of molecular weight of at least 5,000. While the polymer composition itself may be capable of binding to cellulose, this is not unexpected, and there is no disclosure of a polysaccharide conjugate that is capable of binding to cellulose.
U.S. Pat. No. 2,949,397 concerns use of mineral filler coated, at least partially, with water-dispersed organic colloid, to promote retention of filler in cellulose fibres in paper making. The colloid may be e.g. a galactomannans, or substituted mannan such as locust bean gum and guar gum. The coated filler is attracted to cellulose fibres by electrostatic action. The filler and colloid are mixed together, but separate on standing and hence are in the form of a simple mixture not a polysaccharide conjugate.
The paper by Hayashi et al entitled "Pea Xyloglucan and Cellulose" in Plant Physiol. (1987) 83, 384-389 describes investigations of binding of pea xyloglucan to cellulose, using fluorescein-labelled xyloglucan prepared by treating xyloglucan with CNBr and incubating with fluoresceinamine, and also using radioiodinated xyloglucan prepared by reaction of 125, with the fluorescein moiety on xyloglucan. These labels were used to trace the binding of the polysaccharide and are among the smallest molecular label entities known.
The present invention is based on the surprising discovery that polysaccharides with much larger attached entities than those used by Hayashi et al can still bind rapidly with high efficiency to cellulose by polysaccharide:polysaccharide interaction. This is surprising because binding occurs at multiple sites along the backbones of the polysaccharides, rather than at a single binding site as with antibody-antigen interactions, and it would have been predicted that binding would have been disrupted by the attachment of large entities to cellulose-binding polysaccharides. The invention thus opens up the possibility of using polysaccharides to target attached entities to cellulose, e.g. in fabric, paper, etc.